Time to progression by expression level. Box Plot Analyses of the association between lengths of time to progression according to the expression levels of a) total EGFR, b) phosphorylated EGFR, c) phosphorylated Akt, d) phosphorylated Stat3 and e) phosphorylated Erk1/2. Time to progression is expressed in months. Expression levels are expressed in four categories zero, low, moderate, moderate-high, and high, where zero represents samples with no detected signal, low for scores between 1 and 10, moderate for scores between 11 and 100, moderate-high for scores between 101 and 200 and high for scores between 201 and 300. Each box represents the TTP values between the 1st and the 3rd quartile. The line across each box represents the median TTP. The dash at the end of the lines represents the maximum and minimum TTP. The crosses represent the mean TTP for each category.